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Ronald Greek

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since Oct 15, 2010
Outside Yuma, Arizona
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Recent posts by Ronald Greek

Inquiry – Moringa in Permaculture
Can you direct me to any resource showing moringa integrated into a multi-layer permaculture system?
We have around 20 moringa trees growing around our present home. Although I've also been growing other food plants around the trees, if someone has already determined a viable permaculture guild incorporating the moringa, I'd like to avoid "re-inventing the wheel".

Get a chart of the solar exposure for your area so you can predict the location of the sun throughout the year, see:

In appropriate locations position something like wicking garden beds, growing edible tree or vine crops.

Set up your plumbing to route the grey water to beds to avoid using "good" water.
For low-energy use home design / construction ideas check Mike Reynolds "earthship" ideas.

His three Earthship books are available free to read online:

Seminar on earthships by Mike Reynolds, two multi-hour sessions.

Garbage Warrior (His fight with zoning, inspectors, etc)

Another high thermal mass design site is:

This site emphasizes dry stacked concrete block, with both sides then coated with a single layer of fiber reinforced, surface bonding cement ("structural stucco").

the See:

For shelter that saves on HVAC energy, see also the book Passive Annual Heat Storage, where author John Hait indicates that insulating the soil out something like 20 fee from your underground home creates a large soil thermal storage area which can be utilized by buried air/water circulating tubes, with modest blower/pump power gaining access to a lot of stored thermal difference. An above ground home may need a lot of insulation to make up for the surrounding thermal storage of an underground home.

7 years ago
A planting approach that has worked well for us in Yuma, AZ are recessed into the ground versions of “wicking beds”,… which are essentially large Earthboxes.

A primitive description of a quick and dirty BIG “Earthbox”. Dig a hole, say 4’ x 8’ x 1-1/2’ deep. Line with heavy duty plastic. Using a 4’ wide roll of fiberglass plant blocking cloth line the bottom of the hole, flood with about 3” of water and fill to top of water with volcanic rock (lots of pores). Fold another layer of cloth over and cut from roll. Push cloth down into rocks. A piece of plastic pipe big enough to reach into, as long as the bed is deep. Slice top cloth and insert pipe vertical, down to bottom cloth. Slice drains around the walls just below the level of the top cloth.

Put in your wood & soil. We then "mulched" the top with pieces of old carpet, upside down with holes cut for plants. Do the bulk of the watering via the stand pipe.

More info on wicking type garden beds is at:
8 years ago
Per the CIA World Fact Book, and if I’ve done the conversion right, the U.S. has around 400 million arable acres.

If the Dr Pimentel figure of 1.2 acres per person is right, we in the U.S. need to wake up, because his number puts the upper U.S. population limit at 339 million. As of 27 APR 2012 the U.S. census puts the population at 313 million. As to how much of that land can remain arable given ground water depletion, and modern crop / industrial farming dependency on chemical fertilizers, pesticides, fuel, etc., can only lead to a bad-news guess.
9 years ago
Notes from numbers I looked up a while ago…

For more of the notes see

Assume incoming solar, when 90 degrees to the receiving surface, is about 1 kw.

Plants have limits on their rate of converting light to stored energy. Remember that plant biological processes continue at night, and that this uses up some of the energy accumulated in the presence of light. I've read that the overall theoretical efficiency of photosynthesis may be 4.5%. At 6 hour exposure, and if you could eat the entire plant, this would be an area 9 feet on a side. I've no idea what the crop would be, but you would probably be able to watch it grow…

In various sources I find that overall photosynthesis efficiency in open nature and for typical food crops (corn,wheat,rice) is .1% to .2%. For 1/10% efficiency, each of us requires 21,600 sq. ft. /hours per day. With an average of 6 hours solar exposure per day this requires a fully productive food crop area of 3,600 sq. ft., 1,800 for 2/10% This is an area much less than the 1/4 acre per person typically available for manual farming (see information on farming in Cuba post-USSR), yet higher than the 1,000 sq. ft. information from Ecology Action. More (concentrated) sun is not the answer. C3 crops (wheat, barley rice, sugar beet, potatoes) all have FALLING conversion efficiency rates as light intensity goes above 20% of full sunlight.

Potato efficiency goes up to .4%, so with 6 hours exposure you need a minimum of 900 sq. ft. In various places, I've read the most "efficient" crop is claimed to be spirulina, with production of between 5 and 15 gram per sq. yd. per day. If each gram is around 5 calories, we get somewhere between 243 ft. sq. to 720 ft. sq. per person. At the upper level of production, is we're still assuming an average of 6 hours good sun exposure, we're looking at just under 2% efficiency on converting sunlight to food energy.

While I do not really expect to find a more efficient crop than algae, perhaps hydroponic or aeroponic methods can bring up the efficiency of more traditional foods. For those with a sweet tooth, Sugar cane (a C4 crop) comes in at a yearly average of 1%, requiring 360 sq. ft. with 6 hours sunlight, and with crops such as corn and sorghum can utilize higher sun intensity.
9 years ago
The wife seems to think I’m nuts… With that caveat presented…

How about containers of water, block of metal, rock, etc. heated in a “solar oven” and kept swapped out?
9 years ago
Research "Passive Annual Heat Storage" in particular materials by John Hait. While the focus is earth sheltered housing, the heat / cool storage and exchange methods of insulated earth and buried tubes should be applicable to any structure.

... I guess you wouldn't like our Arizona 120 degree summer days...
9 years ago
Try thinking tent in the arctic… Less severe, a canopy bed, which originated as a means to preserve heat.
9 years ago
Mike Reynolds and his Earthship folks deal with rainwater for household use.

His three books have been available online at

Youtube has several video’s of what appear to be recordings of class sessions he has presented, which include rainwater collection and use.
9 years ago
My broad brushstroke notes are online at

While a lot of energy from the sun may reach earth, collecting it, and getting it to a type you need can be a challenge.  At 10 degrees above the horizon, there may be available up to 50% of the total solar power, but is it worth having photovoltaic or heat panels tracking over that far, and is the E/W spacing required for such a low angle worth it?  If you panels are two feet wide, to not shade each other on the E/W axis when tilted to only 10 degrees up from the horizon, they must be spaced apart at around twelve feet.  If you limit your morning/evening aim to 30 degrees above the horizon the same two foot wide panels need to be spaced only four feet apart. 

Depending upon factors such as your latitude, time of the year, and physical barriers, the difference between ten and thirty degrees may be a lot of solar sky-time missed.  With the charts from U.Oregon, you can estimate the potential collection time throughout the year. 
To obtain a chart of the solar path in your area, see the University of Oregon website:

A website to work right triangles is at:

Remember that if a solar panel is partially shaded, most lose a significant portion of their power generating capability, well beyond the percent of the panel shaded.

9 years ago